What Is Lean Construction? Definition and Principles

If you ever get asked to take part in a lean construction project, it may offer a fresh perspective on building. Lean construction principles — and the practices that flow from them — not only transform projects, but have the potential to transform entire companies. Let's take a look at the key principles of lean construction.

What is lean construction?

Lean construction is a relationship-oriented, production management-based approach to construction project delivery that emphasizes the management and design of construction processes, as opposed to just the end product. At heart, its main goals are maximizing stakeholder value while minimizing waste — all while heavily emphasizing inter-team collaboration.

In practice, working lean means you can reliably release work from one construction process to the next. Just imagine being able to turn the building over to whoever is next in line to do their work and know everything will proceed as planned. The authors of Foundations of Lean Construction compare the realization people have when they grasp reliability to the moment when they learn to ride a bike. Suddenly, they feel a new freedom and get a fresh sense of speed and range. 

When someone grasps the idea of reliability in construction, they feel empowered by the notion that they can change design, supply, assembly, and control to get better results, knowing it will work.

Lean Construction principles

Construction projects have phases, beginning with design and ending with closeout. Each stakeholder performs their function as assigned by contract.

In lean construction, the focus switches from individual stakeholders focused solely on their individual roles to all stakeholders working as a team. When applying lean construction principles, the project takes on extra dimensions as participants consider its entire life cycle when deciding what to build and how to build it.

Focusing on the process and flow

In construction — and many businesses — each participant tends to focus on their own self-interests. This means relationships can remain transactional, with contracts ensuring that outcome. 

But in a lean project, everybody focuses on the construction process. When they follow lean construction practices, they optimize everything for the final product. 

If you are a subcontractor on a lean project, you will take part in design with all the other participants. If you are the general contractor, you and the owner will accept design variations suggested by a subcontractor if it’s best for the project. Regardless of your role on a lean project, you have a voice, and it will be heard.

Lean construction also fits the process custom to the product. So, you don’t build a project component in a certain way just because it’s always done this way. Instead, you use a building method and materials that you and the team have optimized for that component. 

Planning rather than reacting

With the pace of many modern construction projects, teams are used to thinking in the short term. During the design phase of a lean construction project, on the other hand, the participants consider the entire life cycle of the structure. Not just what happens to it at midlife, but also what happens when it’s reached the logical conclusion of its life. 

Lean construction project participants also consider how their individual interests affect each other to align their short-term and long-term interests to the project’s benefit.

Today’s projects foretell success in future projects. What went right and what went wrong is only instructive if you analyze it. In a lean construction project, participants honor the future by incorporating lessons from the past at all levels.

Creating structures to achieve goals

In a lean project, you use a systemic approach when getting ready to begin an activity. Then, people doing the work make a firm commitment to complete it following the requirements. In this way, activities start “at the last responsible moment.” Work is "pulled" rather than "pushed" — this helps increase efficiency and reduces waste.

As work gets underway, everybody tunes into the lean construction practices in use so they can foresee and solve problems that could potentially threaten completion. Commitment is key, and on a lean project, every participant is already committed if they signed on to the project. Plus, they know that help flows in all directions so they are not in it alone. 

Managing the project supply chain

The supply chain on most construction projects is fragmented. Each participant manages their own materials and equipment. Parties to a lean construction project work together to improve supply chain performance, allowing them to free themselves from market variabilities. They can reduce price shocks, shortages, and lead times.

Always working toward continuous improvement

Continuous improvement is a key principle of lean construction. This final principle affects all the others — anywhere things can be improved and optimized can be addressed. According to the Lean Tenets, "Lean encourages teams to come together to create a log of constraints that are limiting or blocking productivity on a project." Perfection is never possible — but constantly striving to improve helps create a more productive environment and enables all the other lean principles.

Benefits of lean construction

If everything on a lean construction project is operating optimally, stakeholder value would be maximized and waste would always be minimized — as is set out in lean's largest goals. But how have the ideals of lean construction performed in the real world?

In a notable 2018 study, companies using the most effective lean methods completed 45% of projects early and delivered 70% of them under budget.  

Turner Construction has implemented the lean construction approach in its enterprise. Turner's lean construction page discusses their use of the approach across the company, as well as an example of how lean was used on The New Canaan Library construction project.

For more studies and downloadable resources about lean construction, visit leanconstruction.org.

Transitioning to lean construction means growth and transformation

While few who have studied lean construction would disagree with its benefits, the transition to it requires changes in human behavior. Companies must figure out how to overcome lean’s contradictions with long-held group behavior.

Those who have transitioned to lean construction have themes in their stories of “urgency, leadership, focus, structure, discipline and trajectory,” making this transition nothing short of a transformation.

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